This invention covers new sulfobetaines as well as a process for the manufacture of these sulfobetaines of the general formula I, ##STR1## in which R.sub.1 represents hydrogen, straight-chained or branched alkyl groups of C.sub.1 to C.sub.22 or benzyl, and R.sub.2 represents straight-chained or branched alkyl groups of the same chain length range as indicated for R.sub.1, wherein R.sub.1 and R.sub.2 may be equivalent or different and may form a heterocyclic ring together with the nitrogen atom to which they are bound, optionally through oxygen.
Internal salts of the general formula I increase the conductivity of solutions and may be employed as conductible coating and antistatic materials. Moreover, if R.sub.1 represents straight-chained or branched alkyl groups with 6-22 C-atoms, these sulfobetaines will have valuable surface tension qualities; they may then be employed as thermostable antistatic agents for synthetic plastic materials and as coating agents for all kinds of surfaces, for instance in sheets and woven fabrics. They may be employed as emulsifiers and flotation agents, as dyeing agents and as a component of laundry and cleaning agents at low temperatures for energy-saving laundering processes because of their excellent cleaning power. Some representatives of this new class of substances have exceptional foaming ability so that they are suitable for the manufacture of dry cleaning foams. These sulfobetaines are easily mixed with other surface-active substances, for instance with nonionics. Their excellent solubility in non-aqueous systems opens possibilities of application in the manufacture of stable OW (oil-in-water) and WO (water-in-oil)-emulsions or--in combination with biologically active substances--for use in agents with improved operational value, for instance for improved plant protection agents. They may further be employed as additives in oils.
Sulfobetaines are known in which the cation is not a part of the ring system. These are preferably obtained by alkylation of tert. amines with derivatives of hydroxyalkane sulfonic acids (Parris, Weil, Linfield, J. Amer. Oil Chem. Soc. 53 (1976) 97; DD-PS 139719). Above all, however, the propane sulfone serves to introduce a sulfopropyl group (DE-AS 2431031; DE-AS 2409412). Besides the disadvantageous multiple stages of this process, a further disadvantage of the principally used processes involving propane sulfone is that propane sulfone has been recognized as constituting a dangerous carcinogen and, because of this, it was necessary to deploy precautionary measures, incurring considerable expenses (H. Druckrey and colleagues, Z. Krebsforschung 75 (1970) 69; Reg. of Toxic Effects of Chem. Subst., Nat. Inst. for Occupational Safety and Health, Md., U.S. 1975). Further, hydrogen sulfite addition to trialkylallylammonium salts for the synthesis of sulfobetaines has been proposed by Linfield et al. (J. Amer. Oil Chem. Soc. 53 (1976) 60; 55 (1978) 87). The disadvantages of this process are that the products obtained are of little uniformity when air is excluded, and while working under pressure with long reaction times.
DE-OS 2331515 comprises a process for the addition of hydrogen sulfite radicals to unsubstituted olefins, in which transition metals from the first, seventh and eighth secondary group of the Periodic Table are used as catalysts.
However, the olefins used in that process cannot be compared with the dialkyldiallylammonium compounds of the present invention since they are unsubstituted and have isolated double bonds. Thus they differ considerably regarding their electron configuration and reactivity, from the diallylammonium compounds used in the present invention.
It is the object of this invention to manufacture the sulfobetaines of formula I. The process is to be carried out under mild reaction conditions. It should attain a possible quantitative corrosion with short reaction times, high selectivity, and should keep the level of organic waste products at a minimum through the addition of approximate stoichiometric quantities of the reaction partners.